Clippy was unhappy:
```text
error: use of `.unwrap_or_else(..)` to construct default value
--> sdk/src/signer/keypair.rs:171:27
|
171 | let derivation_path = derivation_path.unwrap_or_else(DerivationPath::default);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `derivation_path.unwrap_or_default()`
|
= note: `-D clippy::unwrap-or-else-default` implied by `-D warnings`
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_or_else_default
```
* added realtime cost checking logic to reject block that would exceed max limit:
- defines max limits at block_cost_limits.rs
- right after each bath's execution, accumulate its cost and check again
limit, return error if limit is exceeded
* update abi that changed due to adding additional TransactionError
* To avoid counting stats mltiple times, only accumulate execute-timing when a bank is completed
* gate it by a feature
* move cost const def into block_cost_limits.rs
* redefine the cost for signature and account access, removed signer part as it is not well defined for now
* check if per_program_timings of execute_timings before sending
* Version transaction message and add new message format
* Update abi digest due to message path change
* Update v0.rs
Fix comment
* Update original.rs
* Update message versions name and address map indexes field name
* s/original/legacy
* update comment
* cargo fmt
* Update abi digest due to legacy rename
* feature: add new token program feature
* Fixup test
* Update to spl-token v3.2.0
* Update Cargo.lock + fmt
* Update token program version in fetch-spl.sh
* Bump associated token program to 1.0.3
* Add aToken so
* Move transaction sanitization earlier in the pipeline
* Renamed HashedTransaction to SanitizedTransaction
* Implement deref for sanitized transaction
* bring back process_transactions test method
* Use sanitized transactions for cost model calculation
* Fix link target in doc comment
* Fix formatting of log examples in process_instruction
* Fix doc markdown in solana-gossip
* Fix doc markdown in solana-runtime
* Escape square braces in doc comments to avoid warnings
* Surround 'account references' doc items in code spans to avoid warnings
* Fix code block in loader_upgradeable_instruction
* Fix doctest for loader_upgradable_instruction
